package com.twelvet.gateway.filter;

import com.twelvet.framework.utils.DateUtils;
import com.twelvet.framework.utils.http.ServletUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

import java.util.List;

/**
 * @author twelvet
 * @WebSite www.twelvet.cn
 * @Description: 全局日志拦截器，对请求的API调用过滤，记录接口的请求时间，方便日志审计、告警、分析等运维操作 2. 后期可以扩展对接其他日志系统
 */
@Component
public class ApiLoggingFilter implements GlobalFilter, Ordered {

    private static final Logger log = LoggerFactory.getLogger(ApiLoggingFilter.class);

    private static final String START_TIME = "startTime";

    /**
     * nginx需要配置
     */
    private static final String X_REAL_IP = "X-Real-IP";

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        if (log.isDebugEnabled()) {
            String info = String.format("Method:{%s} Host:{%s} Path:{%s} Query:{%s}",
                    request.getMethod().name(), request.getURI().getHost(),
                    request.getURI().getPath(), request.getQueryParams());
            log.debug(info);
        }
        exchange.getAttributes().put(START_TIME, System.currentTimeMillis());
        return chain.filter(exchange).then(Mono.fromRunnable(() -> {
            Long startTime = exchange.getAttribute(START_TIME);
            if (startTime != null) {
                Long executeTime = (System.currentTimeMillis() - startTime);
                List<String> ips = request.getHeaders().get(X_REAL_IP);
                String ip = ips != null ? ips.get(0) : null;
                String api = request.getURI().getRawPath();

                int statusCode = 500;
                if (exchange.getResponse().getStatusCode() != null) {
                    statusCode = exchange.getResponse().getStatusCode().value();
                }
                // 当前仅记录日志，后续可以添加日志队列，来过滤请求慢的接口
                if (log.isDebugEnabled()) {
                    log.debug(
                            "\n===================Request================>\n来自IP地址：{}\n时间：{}\n地址：{}\n参数：{}\n方式：{}"
                                    + "\n<===================Response================\n状态：{}\n时长：{}毫秒"
                                    + "\n============================================",
                            ip,
                            DateUtils.getTime(),
                            api,
                            request.getQueryParams(),
                            request.getMethod().name(),
                            statusCode,
                            executeTime

                    );
                }
            }
        }));
    }

    @Override
    public int getOrder() {
        return Ordered.LOWEST_PRECEDENCE;
    }

}